Gravity waves on a surface of topological superfluid 3He-B

P.J. Heikkinen, V.B. Eltsov, V.V. Zavjalov

The Spin Supercurrent and Bose-Einstein condensation of magnons similar to an atomic BEC was observed in 1984 in superfluid 3He-B Recently we discovered 2 new types of BEC in superfluid 3He in deformed aerogel. The orbital part of the wave function orients along the deformation and changes the magnon-magnon interaction. We can do it for 3He-A by uniaxially compressing the aerogel along the magnetic field. The other BEC state was observed in 3He-B in aerogel stretched along the magnetic field. Both states show all properties of magnon BEC We have also observed a splitting of NMR lines near Tc, which seems to indicate the formation of a new phase of superfluid 3He in aerogel. The latter looks like an analog of the 3He-A1 phase with strongly enhanced magnetic field.